Brake for electro-magnetic motors



(No Model.)

T. A. EDISON. Brake for Eleotro-Magnetio Motors Patented June 8,1880.

| H H H "I H. I l l l h A HH H l l l l l h l u ihwmrn awed f/ifzlzum 5M.l9 W014 NPEIERS. FNOTO-LITNOGRAPNER, WASHINGTON D c UNITE STATES PATENTOFFICE.

THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.

BRAKE FOR ELECTRO-MAGNETIC MOTORS.

SPECIFICATION formingpart of Letters Patent No. 228,617, dated June 8,1880.

Application filed March 20, 1880.

To all whom at may concern:

Be it'known that 1, Thomas A. EDIsoN, of Menlo Park, in the county ofMiddlesex and State of New Jersey, have invented a new and usefulImprovement in Electro-Motors, (Case No. 207,) and I do hereby declarethat the followingis a full and exact description of the same, referencebeing had to the accompanying drawings, and to the letters of referencemarked thereon.

In using electro-motors, especially for actuati n g light machinery, itis very desirable that the rate of speed of the actuated machine beunder control of the operator, and that the means of control be simple,effectual, and easy of application. Hitherto this has been attemptedonly through controlling the electric circuit to the motor, breaking orclosing it in whole or in part. This breaking of the circuit isdestructive of the contact-points, and ordinarily efiects only startingand stoppiu g of the machine, and does not regulate the speed of themachine while running. I propose to control the speed of the drivenmachine without affecting the motor by the means more fully hereinafterdescribed and claimed.

In the drawings, Figure 1 is a plan view of an electric motor and standfor a machine to be actuated thereby. Fig. 2 is an en d view of thesame, and Fig. 3 a front view.

A is any suitable electro-motor, in which R is the rotating armature, onwhose shaft is a commutator, upon which press the springs or brushes aa, for completing the circuit from the conductors l 2 to the motor.

Upon the shaft T is the pulley 13, secured thereto by friction, thefriction being so adjusted that the pulley and shaft shall be held andmove together when only the resistance of the actuated machine is to beovercome, but that whenever a greater resistance is offered the frictionshall be overcome and the shaft rotate within the pulley withoutrotating it.

From the pulley B a belt, 1), leads to the large fly-pulley (l, securedto the frame of the actuated machine. Upon the shaft of O is the pulleyF, from which. a belt transmits the motion to the actuated machine.

(No model.)

Upon the under side of the table D, or to any convenient part of theframe, is pivoted a brake, (1, adapted to be brought to bear upon thepulley C, but held normally from so doin by a spring, 00. To the brake dispivoted the lever E, which passes down and is connected with atreadle, c, underneath the table. Through this treadle. then, anydesired pressure may be put upon the periphery of the wheel 0,regulating its speed, the current to the motor remaining unaffected andits rotation continued.

A switch, 8, is used for breaking or closing the circuit to the motor.To the switch is attached a lever, L, which passes to the front of themachine, within easy reach of theoperator. The current passes by wire 1across the switch 8 when closed, as shown, through the motor, and out bywire 2, or vice versa. This switch may, if desired, be placed upon theframe or table of the actuated machine.

The form of brake used may be varied. For instance, it may be abelt-tightener, the belt I) being normally loose, and the brake arrangedto tighten it, so that it will take upon the pulleys and transmit motionfrom one to the other.

What I claim is 1. The combination, with an electro-motor, of amechanical brake, adapted to control the speed of the actuated machine,connected to the motor through a pulley fastened to the shaft of themotor by friction, substantially as set forth.

2. The combination, with an electro-motor, of a brake applied to themain driven wheel and controlling the speed of such wheel, but not thatof the motor, substantially as set forth.

3. The combination, with an electro-motor, of a friction-pulley on therotating shaft of the motor and a brake applied to the main driven wheeland adapted to control its speed, substantially as set forth.

This specification signed and witnessed this 10th day of March, 1880.

THOMAS A. EDISON.

Witnesses:

WM. OARMAN, O. P. Mom.

